There are nine metal dice. 1 die is slightly lighter than th... | Riddle

There are nine metal dice. 1 die is slightly lighter than the other 8. If you had a balance scale and only two attempts, how could you figure out which die weighed the least?

Choose any six dice and place three on each side. If they weigh the same than the die is not among those six. If one side is lighter it is among those three. Next you choose any two dice from the remaining pile of chosen three and weigh them against each other. If they weigh the same then the third die is the lightest. If they don't weigh the same than the lighter of the two is the lightest die.

Why this works

This riddle is a classic example of logical deduction using a balance scale. The first step involves selecting six dice and dividing them into two groups of three. If they balance, it confirms that the lighter die is among the three not weighed; if one side is lighter, it narrows down the suspect to that group of three. In the second step, you then take two dice from that lighter group and weigh them against each other. If they balance, the unweighed die is the lightest; if one is lighter, you've found the lightest die! This method efficiently reduces the number of possibilities and cleverly uses the balance scale's properties to solve the riddle within the allowed attempts.

Common Wrong Answers

“Weigh any two dice against each other.”

This method only allows you to find out which of the two weighed more or less, but does not help you identify the lighter die among the nine since you have no information about the other seven dice.

“Weigh one die against another die until you find the lightest one.”

Since you only have two attempts and there are nine dice, weighing one die at a time is inefficient and will not guarantee finding the lighter die within the limited attempts.

“Weigh all nine dice together at once.”

You cannot weigh all nine dice simultaneously on a balance scale and determine which one is lighter; you need to compare weights in groups to isolate the lighter die.

There are nine metal dice. 1 die is slightly lighter than the other 8. If you had a balance scale and only two attempts, how could you figure out which die weighed the least?

Common Wrong Answers

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